It is very hard to find the correct classification when reporting a bug

I find they way https://bugzilla.mozilla.org does much better, and they have a bot that automatically send the report to correct classification based on the written bug report details.

If KDE can’t do something like that, I guess adding classification in KDE wiki would help? like I want to report something related to the panel but don’t know where to report exactly.

No need to overthink about this. In your case, just file it to plasmashell - general. Devs will move it to the right place if necessary.

A lot of subcategories just won’t make sense to end users.

just make it as generic as possible and the bug triage ppl will sort it to the right place.

https://bugzilla.mozilla.org/ is for a much smaller set of software. Whereas the range of what you can open a bug report about in KDE is pretty vast! So there just inherently have to be more options there, which makes it a harder problem to solve.

the first screen is pretty helpful

and you can always just choose the option highlighted.